DESCRIPTION: Female mosquitoes require a blood meal from a vertebrate host to produce eggs. The public health importance of mosquitoes derives from the fact that while obtaining such a blood meal from a human host the mosquito is able to transmit diseases, such as malaria and dengue, which world-wide are responsible for millions of deaths per year. We need to significantly increase our understanding of the biology of mosquitoes. One area that has been neglected, so far, is fundamental metabolic studies directed towards understanding how the female mosquito utilizes the components of the blood meal. At most 20 percent of the blood meal amino acids are used for egg production and the purpose of this proposal is determine the fate of the other 80 percent. Thus, this proposal is concerned with following the fate amino acids derived from blood meal proteins under a variety of nutritional states. In addition, we propose to assess the role of preexisting energy reserves in the female mosquito during blood meal utilization. Once the relevant pathways have been defined, future studies will be concerned with mechanisms that regulate the pathways under different nutritional, behavioral and environmental conditions. In this proposal we plan to quantitatively examine the fate of amino acids derived from blood meal proteins in Aedes aegypti, the vector of dengue fever and Anopheles albimanus, a vector of malaria in Central and South America. The following specific aims are proposed: 1. Determine the metabolic fate of 14C-labeled blood meal protein amino acids. 2. Determine the metabolic fate of preexisting energy stores, specifically glycogen and lipid, following a blood meal. 3. Characterize the metabolism of blood meal protein amino acids.